Mechanical actuators providing movement of a mechanical element in response to an electrical current supplied to a motor are known in various forms. A typical actuator of this type includes a lead screw rotated by an electrical motor. Because of the typical rotational speed of the electric motor, a speed reduction mechanism is interposed between the electric motor and the lead screw. The lead screw engages a threaded element that moves along the lead screw as the lead screw is rotated by the motive force of the electric motor. While such actuators employ a relatively simple design, they lack flexibility. These actuators typically determine the full extension and full retraction of the piston rod using a sliding electrical contact, effectively counting the number of turns of the lead screw. This technique for detecting the full extension and full retraction in order to terminate current flow to the electric motor is subject to wear, vibration, and corrosion.